3-aminoalkyl-2-aryl-indole derivatives and their use as gnrh antagonists

ABSTRACT

The present invention relates to compounds of formula I which are antagonists of gonadotropin releasing hormone (GnRH) activity. The invention also relates to pharmaceutical formulations, the use of a compound of the present invention in the manufacture of a medicament, a method of therapeutic treatment using such a compound and processes for producing the compounds.

[0001] The present invention relates to compounds which are antagonistsof gonadotropin releasing hormone (GnRH) activity. The invention alsorelates to pharmaceutical formulations, the use of a compound of thepresent invention in the manufacture of a medicament, a method oftherapeutic treatment using such a compound and processes for producingthe compounds.

BACKGROUND TO THE INVENTION

[0002] Gonadotropin releasing hormone (GnRH) is a decapeptide that issecreted by the hypothalamus into the hypophyseal portal circulation inresponse to neural and/or chemical stimuli, causing the biosynthesis andrelease of luteinizing hormone (LH) and follicle-stimulating hormone(FSH) by the pituitary. GnRH is also known by other names, includinggonadoliberin, LH releasing hormone (LHRH), FSH releasing hormone (FSHRH) and LH/FSH releasing factor (LH/FSH RF).

[0003] GnRH plays an important role in regulating the action of LH andPSH (by regulation of their levels), and thus has a role in regulatingthe levels of gonadal steroids in both sexes, including the sex hormonesprogesterone, oestrogens and androgens. More discussion of GnRH can befound in WO 98/5519 and WO 97/14697, the disclosures of which areincorporated herein by reference.

[0004] It is believed that several diseases would benefit from theregulation of GnRH activity, in particular by antagonising suchactivity. These include sex hormone related conditions such as sexhormone dependent cancer, benign prostatic hypertrophy and myoma of theuterus. Examples of sex hormone dependent cancers are prostatic cancer,uterine cancer, breast cancer and pituitary gonadotrophe adenoma.

[0005] The following disclose compounds purported to act as GnRHantagonists: WO 97/21435, WO 97/21703, WO 97/21704, WO 97/21707, WO55116, WO 98/55119, WO 98/55123, WO 98/55470, WO 98/55479, WO 99/21553,WO 99/21557, WO 99/41251, WO 99/41252, WO 00/04013, WO 00/69433, WO99/51231, WO 99/51232, WO 99/51233, WO 99/51234, WO 99/51595, WO99/51596, WO 00/53178, WO 00/53180, WO 00/53179, WO 00/53181, WO00/53185 and WO 00/53602.

[0006] It would be desirable to provide further compounds, suchcompounds being GnRH antagonists.

SUMMARY OF THE INVENTION

[0007] The present invention accordingly provides a compound of formulaI or a salt, pro-drug or solvate thereof

[0008] wherein

[0009] for A, either:-

[0010] (i) A represents hydrogen or optionally-substituted C₁ to C₈alkyl; or

[0011] (ii) the structure N—A(—R⁴) represents an optionally-substituted3- to 8-membered heterocyclic ring optionally containing from 1 to 3further heteroatoms independently selected from O, N and S;

[0012] B represents a direct bond or optionally substituted C₁ to C₅alkylene;

[0013] C represents a mono- or bi-cyclic aromatic ring structureoptionally having at least one substituent selected from CN, NR⁵R⁶, anoptionally substituted C₁ to C₈ alkyl, optionally substituted C₁ to C₈alkoxy or halo;

[0014] D represents hydrogen; optionally substituted C₁ to C₈ alkyl; or(CH₂)_(b)—R^(a), wherein

[0015] R^(a) represents C₃ to C₈ cycloalkyl and b is zero or an integerfrom 1 to 6;

[0016] E is selected from an optionally substituted 3- to 8-memberedheterocyclic ring containing from 1 to 4 heteroatoms independentlyselected from O, N and S; or a group of formula II; III; IV; V; VI; VIIor VIII

[0017]  wherein het represents an optionally substituted 3- to8-membered heterocyclic ring containing from 1 to 4 heteroatomsindependently selected from O, N and S;

[0018] for X and Y, either:-

[0019] (iii) X represents N and Y represents CN; hydrogen or—CONR^(b)R^(c) where R^(b) and R^(c) are independently selected fromhydrogen and C₁ to C₈ alkyl;

[0020] (iiia) X represents CH and Y represents NO₂; or

[0021] (iv) X—Y represents O;

[0022] for R¹ and R², either:-

[0023] (v) R¹ and R² are independently selected from hydrogen andoptionally substituted C₁ to C₈ alkyl; or

[0024] (vi) R¹ and R² together represent carbonyl; or

[0025] (vii)

[0026]  represents an optionally substituted 3- to 8-memberedheterocyclic ring containing from 1 to 3 further heteroatomsindependently selected from O, N and S, and R² meets the definition inoption (v);

[0027] R³ meets the definition in option (vii) or represents hydrogen oroptionally substituted C₁ to C₈ alkyl;

[0028] R⁴ meets the definition in option (ii) or when A meets thedefinition in option (i) R⁴ represents hydrogen or optionallysubstituted C₁ to C₈ alkyl;

[0029] R⁵ and R⁶ are independently selected from hydrogen; optionallysubstituted C₁ to C₈ alkyl and optionally substituted aryl;

[0030] for R⁷ and R^(7a), either:-

[0031] (viii) R⁷ and R^(7a) are independently selected from hydrogen oroptionally substituted C₁ to C₈ alkyl; or

[0032] (ix)

[0033]  represents an optionally substituted 3 to 7-membered cycloalkylring;

[0034] For R⁸ and R⁹, either:-

[0035] (x) R⁸ is selected from hydrogen; optionally substituted C₁ to C₈alkyl; optionally substituted aryl; —R^(d)—Ar, where R^(d) represents C₁to C₈ alkylene and Ar represents optionally substituted aryl; andoptionally substituted 3- to 8-membered heterocyclic ring optionallycontaining from 1 to 3 further heteroatoms independently selected fromO, N and S; and R⁹ is selected from hydrogen; optionally substituted C₁to C₈ alkyl and optionally substituted aryl;

[0036] (xi) wherein E represents a group of formula II or III, then thegroup NR⁸(—R⁹) represents an optionally substituted 3- to 8-memberedheterocyclic ring optionally containing from 1 to 3 further heteroatomsindependently selected from O, N and S; or

[0037] (xii) wherein E represents structure VI,

[0038]  represents an optionally substituted 3- to 8-memberedheterocyclic ring optionally containing from 1 to 4 heteroatomsindependently selected from O, N and S;

[0039] with the proviso that:

[0040] when A is C₁ to C₈ alkyl or the structure N—A(—R⁴) represents anoptionally-substituted 3- to 8-membered heterocyclic ring containingfrom 1 to 3 heteroatoms independently selected from O, N and S; Xrepresents N and Y represents CN or hydrogen, X represents CH and Yrepresents NO₂ or X—Y represents O; then the optional substituents on Aare not selected from optionally substituted phenyl or anoptionally-substituted 3- to 8-membered heterocyclic ring.

[0041] The present invention also provides a pharmaceutical formulationcomprising such a compound, or salt, pro-drug or solvate thereof, and apharmaceutically acceptable diluent or carrier.

[0042] Furthermore, the present invention provides the following uses ofthe compound, or salt, pro-drug or solvate thereof:-

[0043] (a) use in the manufacture of a medicament for antagonisinggonadotropin releasing hormone activity;

[0044] (b) use in the manufacture of a medicament for administration toa patient, for reducing the secretion of luteinizing hormone by thepituitary gland of the patient; and

[0045] (c) use in the manufacture of a medicament for administration toa patient, for therapeutically treating and/or preventing a sex hormonerelated condition in the patient.

[0046] The present invention also relates to a method of antagonisinggonadotropin releasing hormone activity in a patient, comprisingadministering the compound, or salt, pro-drug or solvate thereof, to thepatient.

[0047] In addition, the invention provides a process of producing thecompound, or salt, pro-drug or solvate thereof.

DETAILED DESCRIPTION OF THE INVENTION

[0048] As discussed above, the present invention provides a compound offormula I or a salt, pro-drug or solvate thereof

[0049] wherein

[0050] for A, either:-

[0051] (i) A represents hydrogen or optionally-substituted C₁ to C₈alkyl (preferably, C₁ to C₄ alkyl, for example methyl or ethyl); or

[0052] (ii) the structure N—A(—R⁴) represents a optionally-substituted3- to 8-membered heterocyclic ring (preferably, a 5- or 6-memberedmonocyclic ring) optionally containing from 1 to 3 (eg, 1) furtherheteroatoms independently selected from O, N and S.

[0053] When the structure N—A(—R⁴) represents a 3- to 8-memberedheterocyclic ring, the heterocyclic ring is preferably selected from anoptionally-substituted group of formula, IX, X and XI:

[0054]  Further preferably when the structure N—A(—R⁴) represents a 3-to 8-membered heterocyclic ring, the heterocyclic ring is selected froma group of formula XII or XIII:

[0055]  wherein R¹² represents C₁ to C₈ alkyl; —(CH₂)_(c)NR^(e)R^(f),where c is zero or an integer from 1 to 4, and R^(e) and R^(f)independently represent hydrogen or C₁ to C₈ alkyl; hydroxy; halo; CN;C₁ to C₈ alkoxy; or CF₃.

[0056] B represents a direct bond or optionally substituted C₁ to C₅alkylene (preferably, C₁ to C₄ alkylene, for example methylene orethylene).

[0057] C represents a mono- or bicyclic aromatic ring structure(preferably, phenyl) optionally having at least one substituent (eg, 1,2 or 3 substituents) selected from CN, NR⁵R⁶, an optionally substitutedC₁ to C₈ alkyl (preferably, C₁ to C₄ alkyl, eg, methyl or ethyl),optionally substituted C₁ to C₈ alkoxy (preferably, C₁ to C₆ alkoxy, eg,methoxy, ethoxy or tert-butoxy) or halo (eg, F, Br or Cl).

[0058] Preferably, C represents

[0059]  wherein Me represents methyl.

[0060] D represents hydrogen; optionally substituted C₁ to C₈ alkyl(preferably, C₁ to C₆ alkyl, eg, methyl, ethyl or ten-butyl); or(CH₂)_(b)—R^(a), wherein R^(a) represents C₃ to C₈ cycloalkyl (eg, C₃,C₄, C₅ or C₆ cycloalkyl) and b is zero or an integer from 1 to 6.

[0061] E is selected from an optionally substituted 3- to 8-memberedheterocyclic ring (preferably, a 5- or 6-membered monocyclic ring)containing from 1 to 4 (eg, 1 or 2) heteroatoms independently selectedfrom O, N and S; or a group of formula II; III; IV; V; VI; VII or VIII

[0062]  wherein het represents an optionally substituted 3- to8-membered heterocyclic ring (preferably, a 5- or 6-membered monocyclicring) containing from 1 to 4 (eg, 1 or 2) heteroatoms independentlyselected from O, N and S.

[0063] Preferably, E represents

[0064] (a) structure II of the sub-formula

[0065]  wherein Me represents methyl;

[0066] (b) structure II, wherein

[0067]  represents cyclopropyl or cyclobutyl; or

[0068] (c) structure VIII wherein R⁷ and R^(7a) each represent methyl.

[0069] For X and Y, either:-

[0070] (iii) X represents N and Y represents CN; hydrogen or—CONR^(b)R^(c) where R^(b) and R^(c) are independently selected fromhydrogen and C₁ to C₈ alkyl;

[0071] (iiia) X represents CH and Y represents NO₂; or

[0072] (iv) X—Y represents O.

[0073] Preferably X and Y represent either:-

[0074] (a) X represents CH and Y represents NO₂;

[0075] (b) X represents N and Y represents CN; or

[0076] (c) X represents N and Y represents hydrogen.

[0077] Further preferably X and Y represent either:-

[0078] (a) X represents CH and Y represents NO₂; or

[0079] (b) X represents N and Y represents CN;

[0080] In a further embodiment of the invention X represents N and Yrepresents —CONR^(b)R^(c) wherein R^(b) and R^(c) are as defined above.

[0081] For R¹ and R² either:-

[0082] (v) R¹ and R² are independently selected from hydrogen andoptionally substituted C₁ to C₈ alkyl (preferably, C₁ to C₆ alkyl, eg,methyl, ethyl or tert-butyl); or

[0083] (vi) R¹ and R² together represent carbonyl; or

[0084] (vii)

[0085]  represents an optionally substituted 3- to 8-memberedheterocyclic ring (preferably, a 5- or 6-membered monocyclic ring)containing from 1 to 3 (eg, 1 or 2) further heteroatoms independentlyselected from O, N and S, and R² meets the definition in option (v).

[0086] In one embodiment, R¹ and R² each represent hydrogen and Brepresents C₁ alkylene.

[0087] In a further embodiment of the invention R¹ represents H R²represents methyl and B represents C₁ alkylene.

[0088] R³ meets the definition in option (vii) or represents hydrogen oroptionally substituted C₁ to C₈ alkyl (preferably, C₁ to C₆ alkyl, eg,methyl, ethyl or tert-butyl).

[0089] R⁴ meets the definition in option (ii) or when A meets thedefinition in option (i) R⁴ represents hydrogen or optionallysubstituted C₁ to C₈ alkyl (preferably, C₁ to C₆ alkyl, eg, methyl,ethyl or tert-butyl).

[0090] R⁵ and R⁶ are independently selected from hydrogen; optionallysubstituted C₁ to C₈ alkyl (preferably, C₁ to C₆ alkyl, eg, methyl,ethyl or tert-butyl); and optionally substituted aryl (eg, phenyl).

[0091] For R⁷ and R^(7a), either:-

[0092] (viii) R⁷ and R^(7a) are independently selected from hydrogen oroptionally substituted C₁ to C₈ alkyl (preferably, C₁ to C₆ alkyl, eg,methyl, ethyl or tert-butyl; in one embodiment R⁷ and R^(7a) are bothmethyl); or

[0093] (ix)

[0094]  represents an optionally substituted 3 to 7-membered (eg, 3-,4-, 5- or 6-membered) cycloalkyl ring;

[0095] For R⁸ and R⁹, either:-

[0096] (x) R⁸ is selected from hydrogen; optionally substituted C₁ to C₈alkyl (preferably, C₁ to C₆ alkyl, eg, methyl, ethyl or tert-butyl; inone embodiment both R⁸ and R⁹ are ethyl); optionally substituted aryl(eg, optionally substituted phenyl); —R^(d)—Ar, where

[0097] R^(d) represents C₁ to C₈ alkylene (preferably, C₁ to C₆alkylene, eg, methylene or ethylene) and Ar represents optionallysubstituted aryl (eg, optionally substituted phenyl); and an optionallysubstituted 3- to 8-membered heterocyclic ring (preferably, a 5- or6-membered monocyclic ring) containing from 1 to 3 (eg, 1 or 2) furtherheteroatoms independently selected from O, N and S; and R⁹ is selectedfrom hydrogen; optionally substituted C₁ to C₈ alkyl (preferably, C₁ toC₆ alkyl, eg, methyl, ethyl or tert-butyl) and optionally substitutedaryl (eg, optionally substituted phenyl); or

[0098] (xi) wherein E represents a group of formula II or III, then thegroup NR⁸(—R⁹) represents an optionally substituted 3- to 8-memberedheterocyclic ring (preferably, a 5- or 6-membered monocyclic ring)containing from 1 to 3 (eg, 1 or 2) further heteroatoms independentlyselected from O, N and S; or

[0099] (xii) wherein E represents structure VI,

[0100]  represents an optionally substituted 3- to 8-memberedheterocyclic ring (preferably, a 5- or 6-membered monocyclic ling)containing from 1 to 4 (eg, 1 or 2) heteroatoms independently selectedfrom O, N and S;

[0101] with the proviso that:

[0102] when A is C₁ to C₈ alkyl or the structure N—A(—R⁴) represents anoptionally-substituted 3- to 8-membered heterocyclic ring containingfrom 1 to 3 heteroatoms independently selected from O, N and S; Xrepresents N and Y represents CN or hydrogen, X represents CH and Yrepresents NO₂ or X—Y represents O; then the optional substituents on Aare not selected from optionally substituted phenyl or anoptionally-substituted 3- to 8-membered heterocyclic ring.

[0103] Whilst pharmaceutically-acceptable salts of compounds of theinvention are preferred, other non-pharmaceutically-acceptable salts ofcompounds of the invention may also be useful, for example in thepreparation of pharmaceutically-acceptable salts of compounds of theinvention.

[0104] In the present specification, unless otherwise indicated, analkyl, alkylene or alkenyl moiety may be linear or branched.

[0105] The term “alkylene” refers to the group —CH₂—. Thus, C₈ alkylenefor example is —(CH₂)₈—.

[0106] The term “aryl” refers to phenyl or naphthyl.

[0107] The term “carbamoyl” refers to the group —CONH₂.

[0108] The term “halo” refers to fluoro, chloro, bromo or iodo.

[0109] The term “heterocyclic ring” refers to a 5-10 membered aromaticmono or bicyclic ring or a 5-10 membered saturated or partiallysaturated mono or bicyclic ring, said aromatic, saturated or partiallyunsaturated rings containing up to 5 heteroatoms independently selectedfrom nitrogen, oxygen or sulphur, linked via ring carbon atoms or ringnitrogen atoms where a bond from a nitrogen is allowed, for example nobond is possible to the nitrogen of a pyridine ring, but a bond ispossible through the 1-nitrogen of a pyrazole ring. Examples of 5- or6-membered aromatic heterocyclic rings include pyrrolyl, furanyl,imidazolyl, triazolyl, pyrazinyl, pyrimidinyl, pyridazinyl, pyridinyl,isoxazolyl, oxazolyl, 1,2,4 oxadiazolyl, isothiazolyl, thiazolyl andthienyl. A 9 or 10 membered bicyclic aromatic heterocyclic ring is anaromatic bicyclic ring system comprising a 6-membered ring fused toeither a 5 membered ring or another 6 membered ring. Examples of 5/6 and6/6 bicyclic ring systems include benzofuranyl, benzimidazolyl,benzthiophenyl, benzthiazolyl, benzisothiazolyl, benzoxazolyl,benzisoxazolyl, indolyl, pyridoimidazolyl, pyrimidoimidazolyl,quinolinyl, isoquinolinyl, quinoxalinyl, quinazolinyl, phthalazinyl,cinnolinyl and naphthyridinyl. Examples of saturated or partiallysaturated heterocyclic rings include pyrrolinyl, pyrrolidinyl,morpholinyl, piperidinyl, piperazinyl, dihydropyridinyl anddihydropyrimidinyl.

[0110] The term “aromatic ring” refers to a 5-10 membered aromatic monoor bicyclic ring optionally containing up to 5 heteroatoms independentlyselected from nitrogen, oxygen or sulphur. Examples of such “aromaticrings” include: phenyl, pyrrolyl, furanyl, imidazolyl, triazolyl,pyrazinyl, pyrimidinyl, pyridazinyl, pyridinyl, isoxazolyl, oxazolyl,1,2,4 oxadiazolyl, isothiazolyl, thiazolyl and thienyl. Preferredaromatic rings include 'phenyl, thienyl and pyridyl.

[0111] The symbol

[0112] denotes where the respective group is linked to the remainder ofthe molecule.

[0113] Where optional substitution is mentioned at various places, thisrefers to one, two, three or more optional substituents. Unlessotherwise indicated above (ie, where a list of optional substituents isprovided), each substituent can be independently selected from C₁ to C₈alkyl (eg, C₂ to C₆ alkyl, and most preferably methyl, ethyl ortert-butyl); C₃ to C₈ cycloalkoxy, preferably cyclopropoxy, cyclobutoxyor cyclopentoxy; C₁ to C₆ alkoxy, preferably methoxy or C₂ to C₄ alkoxy;halo, preferably Cl or F; Hal₃C—, Hal₂CH—, HalCH₂—, Hal₃CO—, Hal₂CHO orHal CH₂O, wherein Hal represents halo (preferably F); R^(g)CH₂O—,R^(h)C(O)N(R)—, R^(h)SO₂N(R)— or R^(g)—R^(h)N—, wherein R^(g) and R^(h)independently represent hydrogen or C₁ to C₈ alkyl (preferably methyl orC₂ to C₆ alkyl or C₂ to C₄ alkyl), or R^(g)—R^(h)N— represents anoptionally substituted C₃ to C₈, preferably C₃ to C₆, heterocyclic ringoptionally containing from 1 to 3 further heteroatoms independentlyselected from O, N and S; hydrogen; or R^(k)C(O)O— or R^(k)C(O)—, R^(k)representing hydrogen, optionally substituted phenyl or C₁ to C₆ alkyl(preferably methyl, ethyl, iso-propyl or tert-butyl). For optionalsubstitution of the heterocyclic ring represented by R^(g)—R^(h)N—, atleast one (eg, one, two or three) substituents may be providedindependently selected from C₁ to C₆ alkyl (eg, C₂ to C₄ alkyl, morepreferably methyl); phenyl; CF₃O—; F₂CHO—; C₁ to C₈ alkoxy, preferablymethoxy, ethoxy or C₃ to C₆ alkoxy; C₁ to C₈ alkoxyC(O), preferablymethoxycarbonyl, ethoxycarbonyl, tert-butoxycarbonyl or C₃ to C₆alkoxyC(O)—; phenoxycarbonyl; phenoxy; C₁ to C₈ alkanoyl, preferablyacetyl, ethanoyl or C₃ to C₆ alkyanoyl; carboxy; C₁ to C₈ alkylS(O)_(nn)wherein nn is an integer between 0 and 2, preferably methylthio,ethylthio, C₃ to C₆ alkylthio, methylsulphinyl, ethylsulphinyl, C₃ to C₆alkylsulphinyl, methylsulphonyl, ethylsulphonyl or C₃ to C₆alkylsulphonyl; hydroxy; halo (eg, F, Cl or Br); R^(m)R^(n)N— whereR^(m) and R^(n) are independently hydrogen or C₁ to C₆ alkyl (preferablyC₂ to C₄ alkyl, more preferably methyl, most preferablyR^(m)=R^(n)=methyl); and nitro.

[0114] Where optional substitution of a ring is mentioned at variousplaces, this most preferably refers to one, two, three or moresubstituents selected from C₁ to C₈ alkyl (eg, C₂ to C₆ alkyl, and mostpreferably methyl); C₁ to C₈ alkoxy, preferably methoxy, ethoxy or C₃ toC₆ alkoxy; C₁ to C₈ alkylS(O)_(nn) wherein nn is an integer between 0and 2, preferably methylthio, ethylthio, C₃ to C₆ alkylthio,methylsulphinyl, ethylsulphinyl, C₃ to C₆ alkylsulphinyl,methylsulphonyl, ethylsulphonyl or C₃ to C₆ alkylsulphonyl; halo (eg, F,Cl or Br); CN; and NO₂.

[0115] Preferred optional substituents on A when A is C₁ to C₈ alkylinclude: optionally-substituted phenyl or an optionally substituted 3-to 8-membered heterocyclic ring containing from 1 to 4 heteroatomsindependently selected from O, N and S.

[0116] Preferred optional substituents when the structure N—A(—R⁴)represents a 3- to 8-membered heterocyclic ring include: C₁ to C₄ alkyl,N—(C₁ to C₄ alkyl)amino, N,N-di-(C₁ to C₄ alkyl)amino, CN, halo,carbamoyl, NHC(O)—R^(p), C(O)NH—R^(p), NHS(O)_(nn)R^(p), C₁ to C₄alkylS(O)_(nn); wherein nn and mm independently represent an integerbetween 0 and 2 and R^(p) is C₁ to C₄ alkyl.

[0117] Preferred optional substituents on A when the optionalsubstituents is a 3- to 8-membered heterocyclic ring include optionallysubstituted pyridyl, thienyl, piperidinyl, imidazolyl, triazolyl,thiazolyl, pyrrolidinyl, piperazinyl, morpholinyl or imidazolinyl.Further preferred optional substituents include pyridyl, or a group offormula XIV, XV, XVI, XVII, XVIII, XIX or XX:

[0118] wherein

[0119] R¹¹ represents hydrogen; optionally substituted C₁ to C₈ alkyl(preferably, C₁ to C₆ alkyl, eg, methyl, ethyl or tert-butyl); hydroxy;halo (eg, F, Cl or Br); CN; C₁ to C₈ alkoxy (preferably, C₁ to C₆alkoxy, eg, methoxy or ethoxy); or CF₃; and

[0120] R^(11′) represents hydrogen or optionally substituted C₁ to C₈alkyl (preferably, C₁ to C₆ alkyl, eg, methyl).

[0121] A preferred group of compounds of the invention comprises acompound of formula Ia:

[0122] wherein:

[0123] E is selected from a II, III or VIII:

[0124]  and A, B, D, X, Y, R¹, R², R³, R⁴, R⁷, R^(7a) R⁸ and R⁹ are asdefined above; or a salt, pro-drug or solvate thereof.

[0125] A further preferred group of compounds of the invention comprisesa compound of formula Ib:

[0126] wherein:

[0127] E is selected from a group of formula II, III or VIII:

[0128]  and A, B, D, X, Y, R³, R⁴, R⁷, R^(7a), R⁸ and R⁹ are as definedabove; or a salt, pro-drug or solvate thereof.

[0129] A yet further preferred group of compounds of the inventioncomprises a compound of formula Ia or Ib wherein:

[0130] E is a group of formula II:

[0131] NR⁸(—R⁹)represents an optionally substituted 7- to 8-memberedbicyclic heterocyclic ring and A, B, D, X, Y, R³, R⁴, R⁷, R^(7a), R⁸ andR⁹ are as defined above;

[0132] or a salt, pro-drug or solvate thereof.

[0133] Particularly preferred compounds according to the presentinvention are wherein the compound is selected from a compound offormula XXI to XXXI:-

[0134] It is to be understood that, insofar as certain of the compoundsof the invention may exist in optically active or racemic forms byvirtue of one or more asymmetric carbon atoms, the invention includes inits definition any such optically active or racemic form which possessesthe property of antagonizing gonadotropin releasing hormone (GnRH)activity. The synthesis of optically active forms may be carried out bystandard techniques of organic chemistry well known in the art, forexample by synthesis from optically active starting materials or byresolution of a racemic form. Similarly, activity of these compounds maybe evaluated using the standard laboratory techniques referred tohereinafter.

[0135] The invention also relates to any and all tautomeric forms of thecompounds of the different features of the invention that possess theproperty of antagonizing gonadotropin releasing hormone (GnRH) activity.

[0136] It will also be understood that certain compounds of the presentinvention may exist in solvated, for example hydrated, as well asunsolvated forms. It is to be understood that the present inventionencompasses all such solvated forms which possess the property ofantagonizing gonadotropin releasing hormone (GnRH) activity.

[0137] The compounds of Formula I may be administered in the form of apro-drug which is broken down in the human or animal body to give acompound of the Formula I. Examples of pro drugs include in-vivohydrolysable esters of a compound of the Formula I. Various forms ofpro-drugs are known in the art. For examples of such pro-drugderivatives, see:

[0138] a) Design of Prodrugs, edited by H. Bundgaard, (Elsevier, 1985)and Methods in Enzymology, Vol. 42, p. 309-396, edited by K. Widder, etal. (Academic Press, 1985);

[0139] b) A Textbook of Drug Design and Development, edited byKrogsgaard-Larsen and H. Bundgaard, Chapter 5 “Design and Application ofProdrugs”, by H. Bundgaard p. 113-191 (1991);

[0140] c) H. Bundgaard, Advanced Drug Delivery Reviews, 8, 1-38 (1992);

[0141] d) H. Bundgaard, et al., Journal of Pharmaceutical Sciences, 77,285 (1988); and

[0142] e) N. Kakeya, et al., Chem Pharm Bull, 32, 692 (1984).

[0143] An in-vivo hydrolysable ester of a compound of the Formula Icontaining a carboxy or a hydroxy group is, for example, apharmaceutically-acceptable ester which is hydrolysed in the human oranimal body to produce the parent acid or alcohol. Suitablepharmaceutically-acceptable esters for carboxy include C₁ toC₆alkoxymethyl esters for example methoxymethyl, C₁ to₆alkanoyloxymethyl esters for example pivaloyloxymethyl, phthalidylesters, C₃ to C₈cycloalkoxycarbonyloxyC₁ to C ₆alkyl esters for example1-cyclohexylcarbonyloxyethyl; 1,3-dioxolen-2-onylmethyl esters, forexample 5-methyl-1,3-dioxolen-2-onylmethyl; and C₁ toC₆alkoxycarbonyloxyethyl esters.

[0144] An in-vivo hydrolysable ester of a compound of the Formula Icontaining a hydroxy group includes inorganic esters such as phosphateesters (including phosphoramidic cyclic esters) and α-acyloxyalkylethers and related compounds which as a result of the in-vivo hydrolysisof the ester breakdown to give the parent hydroxy group/s. Examples ofα-acyloxyalkyl ethers include acetoxymethoxy and2,2-dimethylpropionyloxy-methoxy. A selection of in-vivo hydrolysableester forming groups for hydroxy include alkanoyl, benzoyl, phenylacetyland substituted benzoyl and phenylacetyl, alkoxycarbonyl (to give alkylcarbonate esters), dialkylcarbamoyl andN-(dialkylaminoethyl)-N-alkylcarbamoyl (to give carbamates),dialkylaminoacetyl and carboxyacetyl.

[0145] A suitable pharmaceutically-acceptable salt of a compound of theinvention is, for example, an acid-addition salt of a compound of theinvention which is sufficiently basic, for example, an acid-additionsalt with, for example, an inorganic or organic acid, for examplehydrochloric, hydrobromic, sulphuric, phosphoric, trifluoroacetic,citric or maleic acid. In addition a suitablepharmaceutically-acceptable salt of a compound of the invention which issufficiently acidic is an alkali metal salt, for example a sodium orpotassium salt, an alkaline earth metal salt, for example a calcium ormagnesium salt, an ammonium salt or a salt with an organic base whichaffords a physiologically-acceptable cation, for example a salt withmethylamine, dimethylamine, trimethylamine, piperidine, morpholine ortris-(2-hydroxyethyl)amine.

[0146] The compounds of formula I can be prepared by a processcomprising a step selected from (a) to (e) as follows, these processesare provided as a further feature of the invention:-

[0147] (a) Reaction of a compound of formula XXXII as follows

[0148] (b) Cleavage of the CN group of compound of formula XXXIII in thepresence of acid to produce compound of formula XXXIV

[0149] (c) Reaction of compound of formula XXXV as follows

[0150] (d) Reaction of compound of formula XXXVII as follows

[0151] (e) Reaction of compound of formula XXXIX as follows

[0152]  and thereafter if necessary:

[0153] i) converting a compound of the formula I into another compoundof the formula I;

[0154] ii) removing any protecting groups;

[0155] iii) forming a salt, pro-drug or solvate.

[0156] It will be appreciated by those skilled in the art that in theprocesses of the present invention certain functional groups such ashydroxyl or amino groups in the starting reagents or intermediatecompounds may need to be protected by protecting groups. Thus, thepreparation of the compounds of formula I may involve, at an appropriatestage, the addition and subsequent removal of one or more protectinggroups.

[0157] The protection and de-protection of functional groups isdescribed in ‘Protective Groups in Organic Chemistry’, edited by J. W.F. McOmie, Plenum Press (1973) and ‘Protective Groups in OrganicSynthesis’, 2nd edition, T. W. Greene and P. G. M. Wuts,Wiley-Interscience (1991).

[0158] A suitable protecting group for an amino or alkylamino group is,for example, an acyl group, for example an alkanoyl group such asacetyl, an alkoxycarbonyl group, for example a methoxycarbonyl,ethoxycarbonyl or tert-butoxycarbonyl group, an arylmethoxycarbonylgroup, for example benzyloxycarbonyl, or an aroyl group, for examplebenzoyl. The de-protection conditions for the above protecting groupsnecessarily vary with the choice of protecting group. Thus, for example,an acyl group such as an alkanoyl or alkoxycarbonyl group or an aroylgroup may be removed for example, by hydrolysis with a suitable basesuch as an alkali metal hydroxide, for example lithium or sodiumhydroxide. Alternatively an acyl group such as a tert-butoxycarbonylgroup may be removed, for example, by treatment with a suitable acid ashydrochloric, sulphuric or phosphoric acid or trifluoroacetic acid andan arylmethoxycarbonyl group such as a benzyloxycarbonyl group may beremoved, for example, by hydrogenation over a catalyst such aspalladium-on-carbon, or by treatment with a Lewis acid for example borontris(trifluoroacetate). A suitable alternative protecting group for aprimary amino group is, for example, a phthaloyl group which may beremoved by treatment with an alkylamine, for exampledimethylaminopropylamine, or with hydrazine.

[0159] A suitable protecting group for a hydroxy group is, for example,an acyl group, for example an alkanoyl group such as acetyl, an aroylgroup, for example benzoyl, or an arylmethyl group, for example benzyl.The de-protection conditions for the above protecting groups willnecessarily vary with the choice of protecting group. Thus, for example,an acyl group such as an alkanoyl or an aroyl group may be removed, forexample, by hydrolysis with a suitable base such as an alkali metalhydroxide, for example lithium or sodium hydroxide. Alternatively anarylmethyl group such as a benzyl group may be removed, for example, byhydrogenation over a catalyst such as palladium-on-carbon.

[0160] A suitable protecting group for a carboxy group is, for example,an esterifying group, for example a methyl or an ethyl group which maybe removed, for example, by hydrolysis, with a base such as sodiumhydroxide, or for example a tert-butyl group which may be removed, forexample, by treatment with an acid, for example an organic acid such astrifluoroacetic acid, or for example a benzyl group which may beremoved, for example, by hydrogenation over a catalyst such aspalladium-on-carbon.

Experimental

[0161] General Reaction Schemes

[0162] In the following schemes wherein Ri, Rii and Riii representoptional substituents on the phenyl ring which are optionally protectedas necessary and R represents a protecting group, group C has beendepicted as substituted phenyl for illustration purposes only. Otherdefinitions of C are also appropriate.

[0163] Tryptamines, such as 3 can be synthesised by the classic Fisherindole synthesis reaction by the condensation of a hydrazine 1 and aketone 2, bearing hydrogen atoms α to the carbonyl (Scheme a). Treatmentof these reactants in a suitable solvent, such as acetic acid, ethanol,tert-butanol, toluene, in the presence of an acid, such as sulphuric,hydrochloric, polyphosphoric and/or a Lewis acid, for example, borontrifluoride, zinc chloride, magnesium bromide, at elevated temperatures(for example 100° C.), gives the desired product. R represents aprotecting group, eg tert-butylcarbamate or phthalimide.

[0164] Tryptamines, such as represented in structure 5, can also be madeusing aldehydes 4, bearing hydrogen atoms α to the carbonyl, bycyclization using the conditions above. In this case the substituent atthe 2-position must be added later (see scheme d).

[0165] Tryptamine may also be synthesised utilising the Granburgreaction, wherein a hyradazine 1 is mixed with ketone 6, bearing achlorine atom γ to the carbonyl, and heated in a suitable solvent suchas ethanol, tert-butanol, toluene at a temperature between 50° C. and120° C. (Scheme c).

[0166] The tryptamine 5 can be treated with a ‘bromine source’, such asmolecular bromide, pyridinium tribromide, pyrrolidone hydrobromide orpolymer supported reagent equivalents, in an inert solvent such aschloroform, methylene chloride at −10° C. to 25° C. to yield the 2-bromocompound 8 (Scheme d). Reaction under Suzuki conditions with apalladium(0) catalyst, a weak base such aqueous sodium carbonate orsaturated sodium hydrogen carbonate and the like, and a substituted arylboronic acid from commercial sources or prepared (as described in:Gronowitz, S.; Hornfeldt, A.-B.; Yang, Y.,-H Chem. Sci. 1986, 26,311-314), in an inert solvent such as toluene, benzene, dioxane, THF,DMF and the like, with heating between 25° C. and 100° C., preferably80° C., for a period of 1-12 hours, to give the desired compound 3.

[0167] The hydrazines 1 can be purchased from commercial sources eitheras a free base or suitable salt (e.g. hydrochloride), which are bothacceptable under the reaction conditions. Hydrazines may be synthesisedby the two-step process of diazotisation of an aniline, under thepreferred conditions of concentrated hydrochloric acid sodium nitrite ata temperature between −10° C. and −5° C., then reduction under thepreferred conditions of tin(II) chloride in concentrated hydrochloricacid at a temperature between −10° C. and −5° C.

[0168] Substituted ketones 2 can be prepared, as outlined in Scheme estarting from appropriate acid chlorides such as 9. Treatment of theacid chloride with N,N-dimethylhydroxylamine hydrochloride in thepresence of an amine base such as triethylamine, and a suitable solventsuch as methylene chloride at a temperature of −10° C. to 25° C., yieldsthe amide 10. Further reaction with a substituted aryl organolithium(prepared essentially as described in Wakefield B, J.; OrganolithiumMethods Academic Press Limited, 1988, pp. 27-29 and references therein)in an inert solvent such as tetrahydrofuran, diethyl ether, benzene,toluene or mixture thereof and the like, at a temperature between −100°C. and 0° C. then quenching of the reaction mixture with a mineral acidsuch as hydrochloric acid, yields the aryl ketone 2.

[0169] Commencing with a readily available amino acid with a suitablechain length [a] 11, the nitrogen atom can be brought in at thebeginning of the synthesis by the route shown in Scheme f. Protection ofthe amine group of 11 with a tert-butylcarbamate group is achieved bycondensation with di-tert-butyl di-carbonate in the presence of an aminebase, for example triethylamine, in an inert solvent such as methylenechloride, chloroform, benzene, toluene, tetrahydrofuran and mixturesthereof and the like, at a temperature of −10° C. to 25° C. Coupling ofthe acid product with N,N-dimethylhydroxylamine in the presence of acoupling reagent 1-(3-dimethylaminopropyl)-3-ethylcarbodiimidehydrochloride (EDC) or 1,3-dicyclohexylcarbodiimide (DCC) or the like,with or without 1-hydroxybenotriazole (HOBt), and suitable amine base,such as triethylamine and the like, in an inert solvent such asmethylene chloride, chloroform, dimethylformamide, or mixture thereof,at or near room temperature for a period of 3 to 24 hours provided thecorresponding coupled product 12. Following the same route describedabove for scheme d, the aryl group can then be installed.

[0170] Scheme g illustrates another method for the synthesis of ketonesuch as 2 and 16, where the nitrogen group is introduced at a latterstage. As above a Weinreb amide 14 can be synthesised from an acidchloride. Treatment with the required amine, in an inert solvent such asTHF, toluene, water and the such like can displace the group X to give17. As above the aryl group can be introduced by displacement of theWeinreb amide with a suitable aryl lithium nucleophile. Alternativelythe nitrogen atom can be introduced already protected as a phthalimideby displacement of the group x by potassium phthalimide, or similar saltthereof, by heating in an inert polar solvent such as DMF, DMSO, TBF,toluene with or without the presence of a catalyst such astetrabutylammonium iodide and the such like, to yield the compound 15.Again displacement of the Weinreb amide with an organolithium speciescompletes the synthesis of a ketone suitable for cyclization under theFischer condition described above for indole synthesis.

[0171] An alternative approach to a phthalimide protected nitrogenketone, such as 16, can be taken by firstly treating a lactone, with anorganolithium species as in the above schemes in a suitable solvent suchas THF or ether at a low temperature of between −100° C. and −50° C. toyield a primary alcohol 18 (Scheme h). The hydroxyl function of 18 isreplaced with a phthalimide group by a Mitsunobu reaction with anactivating agent such as diethyldiazocarboxylate (DEAD),diisopropyldiazocarboxylate or the like with triphenylphosphine,tri-butylphosphine and the like, in an inert solvent such as benzene,toluene, tetrahydrofuran or mixtures thereof to give the desired ketone16.

[0172] If the group D was not present on the starting hydrazine beforecyclization to form an indole it may be added post cyclization by analkylation reaction (19→3). The indole is de-protonated by a strongbase, such as sodium hydride, n-butyl lithium, lithium diisopropylaminesodium hydroxide, potassium tert-butoxide in a suitable inert solventsuch as THF, DMF, DMSO and the such like, and an alkyl halide added andthe mixture stirred at room temperature.

[0173] Depending on the route used above a tryptamine 20 suitable forconversion to a cyano-guandine can be formed by removal of theprotecting group, for example if a tert-butylcarbamate group was usedthen removal is accomplished using a strong acid, for exampletrifluoroacetic acid or hydrochloric acid in an inert solvent such asmethylene chloride, chloroform, THF or dioxane at a temperature between−20 C. and 25° C. A phthalimide group, for example, can be removed byhydrazine in a suitable solvent for example methanol, ethanol, methylenechloride, chloroform, TBF dioxane at a temperature between −20° C. and25° C. The primary amine 20 can be converted to a cyano-guanidine 22 bythe two step process of reaction with diphenyl cyanocarbonimidate in aninert organic solvent such as iso-propyl alcohol, methylene chloride,chloroform, benzene, tetrahydrofuran and the like, at a temperaturebetween −20° C. and 50° C., followed by condensation with anappropriately substituted amine in an inert organic from the list above,with heating at a temperature between −20° C. and 100° C. (Scheme I20→21→22). Further treatment of 22 with 2 molar Hydrochloric acid inmethanol at elevated temperature yields guanidine compounds 23.

[0174] Similarly, reaction with 1,1′-bis(methylthio)-2-nitroethylene inan inert solvent such methylene chloride, chloroform, benzene,tetrahydrofuran and the like, followed by condensation with anappropriately substituted amine in an inert organic solvent from thelist above yields the nitroethyleneimidazo [1,2-a]pyridine 25 (Scheme j,20→24→25).

[0175] Again in a similar fashion the suitable tryptamine 20, derivedfrom de-protection, can be converted to a urea by either directtreatment with an iso-cyanate in an inert solvent such as methylenechloride, chloroform or THF and the such like, or by a two stepprocedure of reaction with triphosgene (20→27) followed by addition ofan amine (27→26), bearing the required substitution to yield 26.

EXAMPLES

[0176] The invention will now be illustrated with the followingnon-limiting Examples in which, unless otherwise stated:

[0177] (i) evaporations were carried out by rotary evaporation in vacuoand work-up procedures were carried out after removal of residual solidssuch as drying agents by filtration;

[0178] (ii) operations were carried out at room temperature, that is inthe range 18-25° C. and under an atmosphere of an inert gas such asargon or nitrogen;

[0179] (iii) yields are given for illustration only and are notnecessarily the maximum attainable;

[0180] (iv) the structures of the end-products of the Formula I wereconfirmed by nuclear (generally proton) magnetic resonance (NMR) andmass spectral techniques; proton magnetic resonance chemical shiftvalues were measured on the delta scale and peak multiplicities areshown as follows: s, singlet; d, doublet; t, triplet; m, multiplet; br,broad; q, quartet, quin, quintet;

[0181] (v) intermediates were not generally fully characterised andpurity was assessed by thin layer chromatography (TLC), high-performanceliquid chromatography (HPLC), infra-red (IR) or NMR analysis;

[0182] (vi) chromatography was performed on silica (Merck Keiselgel:Art.9385);

[0183] (vii) isolute™ refers to silica (SiO₂) based columns withirregular particles with an average size of 50 μm with nominal 60 Åporosity [Source: Jones Chromatography, Ltd., Glamorgan, Wales, UnitedKingdom].

[0184] Abbreviations brine a saturated solution of sodium chloride indistilled water DCC 1,3-dicyclohexylcarbodiimide DEADdiethyldiazocarboxylate DMSO Dimethyl sulphoxide DMF dimethylformamideEDC 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride HOBt1-hydroxybenotriazole IPA isopropyl alcohol RM reaction mixture RT roomtemperature THF tetrahydrofuran

Example 1

[0185] STRUCTURE EXAMPLE

1.01

[0186] Synthesis of this compound is described with reference to SchemeI below.

[0187] Morpholine (260 ml, 3 mmol) was added to a stirred suspension ofL (0.18 mmol) in IPA (2 ml) and the mixture heated at reflux for 36hours. The RM was concentrated in vacuo and the residues purified bychromatography on SiO₂ eluting with 5% MeOH/CH₂Cl₂ to give 1.01 as anoff-white foam white 43.5 mg(46%).

[0188]¹H NMR (300 MHz, CDCl₃) 0.60-0.80 (m,3H); 1.00-1.20 (m,3H); 1.60(s,6H); 2.4 (s,6H); 2.80-3.00 (m,2H); 3.08-3.14 (m,4H); 3.2-3.3 (t,2H);3.3-3.42 (m,2H); 3.5-3.58 (m,4H); 3.62-3.72 (m,2H); 4.5-4.6 (m,1H); 7.03(s,1H); 7.05-7.13 (m,1H); 7.20 (s,2H); 7.2-7.36 (m,1H); 7.42 (s,1H);8.15 (s,1H). MS (ES⁺) m/z (M+H)⁺ 543.39 MS (ES⁻) m/z (M−H)⁻ 541.33

[0189] Following a procedure similar to that described in Example 1, thefollowing compounds were prepared. STRUCTURE EXAMPLE MS (ES)+

1.02 556.74 (M + H)+

1.03 585.55 (M + H)+

1.04 542.54 (M + H)+

1.05 570.51 (M + H)+

1.06 527.48 (M + H)+

1.07 473.48 (M + H)+

Example 2

[0190] EXAM- STRUCTURE PLE

2

[0191] Synthesis of this compound is described with reference to Scheme2 below.

[0192] Methylamine (1 mg, 2.00 mmol) was added to a stirred suspensionof M (46.4 ml, 0.089 mmol) in CH₂Cl₂ (2 ml) and the mixture stirred for60 hrs. The RM was concentrated in vacuo and the residues purified bychromatography on SiO₂ (solute, 10 g), eluting with a gradient 0-10%MeOH/CH₂Cl₂ to give 2.01 as a white solid 31.3 mg(70%).

[0193]¹H NMR (300 MHz, CDCl₃) 0.6-0.8 (m,3H); 1.0-1.2 (m,3H); 1.6(s,6H); 2.35 (s,6H); 2.40-2.60 (m,3H); 2.8-3.0 (m,2H); 3.00-3.60 (m,6H); 4.4-4.9 (m,1H); 6.2-6.6 (m,1H); 7.02 (s,1H); 7.1 (d,1H); 7.15(bs,2H); 7.3-7.45 (m,2H); 8.45 (s,1H); 9.80-10.2 (bm,1H). MS (ES⁺) m/z(M+M)⁺ 506.63 MS (ES⁻) m/z (M−H)⁻ 504.64

Example 3

[0194] STRUCTURE EXAMPLE

3

[0195] Synthesis of this compound is described with reference to Scheme3 below.

[0196] A solution of K (100 mg, 0.25 mmol) in MeOH (5 mL) was treatedwith 2N HCl (2 mL) followed Potassium cyanate (405 mg, 5 mmol). Themixture was stirred for 18 hrs then quenched with saturated NaHCO₃ (aq)(100 mL) and extracted with EtOAc (3×50 mL). The combined organics werewashed with brine (2×50 mL), dried over MgSO₄, filtered and evaporated.The crudes were purified by chromatography on SiO₂ eluting with agradient 0-5% MeOH/CH₂Cl₂ to give 3 as an off-white foam 82.0 mg(73%).

[0197]¹H NMR (300 MHz, CDCl₃) 0.60-0.80 (m,3H); 1.00-1.20 (m,3H); 1.60(s,6H); 2.18 (s,6H); 2.84-3.00 (m,2H); 3.06-4.00 (m,6H); 4.24 (s,2H);4.66-4.72 (m,1H); 7.00-7.1 (m,2H); 7.2 (s,2H); 7.3-7.34 (m,1H); 7.46(s,1H); 8.12 (s,1H). MS (ES⁺) m/z (M+H)⁺ 449.57 MS (ES⁻) m/z (M−H)⁻447.59

Example 4

[0198] STRUCTURE EXAMPLE

4

[0199] Synthesis of this compound is described with reference to Scheme4 below.

[0200] 3-(Methylsulphonyl) pyrrolidine (746 mg, 5 mmol) was added to astirred suspension of Q (547 mg, 1 mmol) in IPA (10 mL) and the mixtureheated at reflux for 18hrs. The RM was concentrated in vacuo and theresidues purified by chromatography on SiO₂ (Isolute, 50 g), elutingwith a gradient 0-10% MeOH/CH₂Cl₂ to give 4 as a white foam 393mg(65.3%).

[0201]¹H NMR (300 MHz, CDCl₃) 1.4-1.8 (m,10H+H₂O); 2.1-2.3 (m,1H);2.3-2.5 (m,7H); 2.8(t,2H); 2.9 (s,3H); 3.1-3.45 (m, 4H); 3.45-3.9(m,7H); 4.45 (t,1H); 7.02 (s,1H); 7.1 (dd,1H); 7.2 (s,2H); 7.3 (d,1H);7.45 (s,1H); 8.2 (s,1H). MS (ES⁺) m/z (M+H)⁺ 603.16 MS (ES⁻) m/z (M−H)⁻601.12

Example 5

[0202] STRUCTURE EXAMPLE

5.01

[0203] Synthesis of this compound is described with reference to Scheme7 below.

[0204] 2N HCl (5 mL) was added to a stirred solution of R (200 mg, 0.331mmol) in dioxane (5 mL) and the resulting solution left to stir for 72hours at room temperature. The reaction mixture was partitioned betweensaturated NaHCO₃ (100 mL) and EtOAc (4×50 mL). Combined organics weredried (MgSO₄), filtered and evaporated to a white foam. This was thenpurified by chromatography on SiO₂ (Varian, 10 g), eluting with agradient 0-10% MeOH/CH₂Cl₂ to give a white foam which was trituratedwith Et₂O (10 mL), filtered and dried under high vacuum to give 5 as awhite powder 99.4 mg (48%).

[0205]¹H NMR (300 MHz, DMSO-D₆+CD₃COOD) □0.50-0.80 (m,3H); 0.90-1.10(m,3H); 1.45 (s,6H); 1.8-2.1 (m,1H); 2.2-2.4 (m,7H); 2.70-3.00 (m,2H);3.00-3.30 (m,4H); 3.30-3.65 (m,6H); 3.65-3.85 (m,1H); 6.87 (d,1H); 6.95(s,1H); 7.17(s,2H); 7.20-7.35 (m,3H); 7.38 (s,1H); 8.50 (d,2H). MS (ES⁺)m/z (M+H)⁺ 622.51.

[0206] Synthesis of R (See Scheme 7)

[0207] 4-Pyrrolidin-3-yl pyridine (100 g, 6.76 mmol) was added to astirred suspension of L (100 g, 1.80 mmol) [See Scheme 1] in IPA (5 ml)and the mixture heated at reflux for 36 hours. The RM was concentratedin vacuo and the residues purified by chromatography on SiO₂ (Isolute,50 g), eluting with a gradient 0-10% MeOH/CH₂Cl₂ to give R as a whitefoam 672 mg(61%).

[0208]¹H NMR (300 MHz, CDCl₃) 0.60-0.80 (m,3H); 1.00-1.20 (m,3H); 1.60(s,6H); 1.80-2.00(m,1H); 2.10-2.30 (m,1H); 2.35 (s,6H); 2.80-3.00(m,2H); 3.10-3.50 (m, 8H); 3.60-3.80 (m,3H); 4.40 (m,1H); 6.97 (s,1H);7.00-7.15 (m,3H); 7.20 (s,2H); 7.28-7.36 (m,1H); 7.41 (s,1H); 8.22(s,1H); 8.48-8.60 (m,2H). MS (ES⁺) m/z (M+H)⁺ 604.56 MS (ES⁻) m/z (M−H)⁻602.54

[0209] Following a procedure similar to that described in Example 5.01,the following compound was prepared. STRUCTURE EXAMPLE MS (ES)+

5.02 596.5 (M + H)+

[0210] Preparation of Starting Materials (1)

[0211] Syntheses for starting materials B, C, D, E and F used in theabove examples are described with reference to Scheme 5 below.

[0212] 2N NaOH (510 ml, 1.02 mol) was added to a stirred solution of A(48.5 g, 205 mmol) in MeOH (550 ml) and the resulting mixture heated atreflux for 2 hours. The RM was concentrated, acidified to pH 4 with 2NHCl and extracted with EtOAc (4×200 ml). The combined organics werewashed with brine (3×150 ml), dried (MgSO₄) filtered and evaporated togive B as a cream powder 40.3 g (95%).

[0213]¹H NMR (300 MHz, CDCl₃) 1.66 (s,6H); 7.55 (m,2H); 8.20 (m,2H).

[0214] O-(7-Azabenzotriazol-1-yl)-N,N,N′,N′-TetramethyluroniumHexafluoro-Phosphate (89.0 g, 290 mmol) was added portion wise to astirred, cooled (0° C.) solution of B (40.3 g, 192 mmol) in DMU (300 ml)and Diethylamine (300 ml). The resulting mixture was left to warm to RTand stir 70 hours. DMF was removed in vacuo and the residuesre-dissolved in EtOAc (500 ml), washed with water (3×200 ml), brine(2×200 ml), dried MgSO₄, filtered and evaporated.

[0215] The crudes were purified by flash chromatography on SiO₂ (600 g,Merck 9385) eluting with 35% EtOAc/i-Hexane. Appropriate fractions werecombined and evaporated to give C as yellow crystalline solid 44.2 g(87%).

[0216]¹H NMR (300 MHz, CDCl₃) 0.60-0.90 (m,3H); 0.90-1.25 (m,3H); 1.58(s,6H); 2.65-2.95 (m, 2H); 3.20-3.45 (m, 2H); 7.40 (m, 2H); 8.20 (m,2H). LCMS (ES⁺) m/z (M+H)⁺ 265.48 (UV 254 nm 100%)

[0217] A solution of C (89.0 g, 338 mmol) in EtOH (2L) was treated with10% Pd/C (50% wet) (10.0 g) then stirred under H₂ (3 Bar) at RT for 3hours. The RM was filtered through diatomaceous earth and evaporated togive D as a tan solid 65.5 g (83%).

[0218]¹H NMR (300 MHz, CDCl₃) 0.60-0.90 (m,3H); 0.90-1.25 (m,3H); 1.48(s,6H); 2.80-3.10 (m,2H); 3.15-3.45 (m,2H); 3.45-3.75 (bs,2H); 6.60-6.70(m,2H); 6.90-7.05 (m, 2H). MS (ES⁺) m/z (M+H)⁺ 235.61

[0219] N-Bromosuccinimide (18.24 g, 102.6 mmol) was added portion wiseto a stirred, cooled (0° C.) solution of D (24.0 g, 102.6 mmol) inCH₂Cl₂ (250 ml) and the mixture stirred for 2 hours. The RM wasevaporated, the residues re-dissolved in EtOAc (200 ml), washed withsaturated NaHCO₃ (aq) (3×200 ml), water (2×200 ml), brine (200 ml),dried MgSO₄, filtered and evaporated. The crudes were purified by flashchromatography on SiO₂ (500 g, Merck 9385) eluting with 5% MeOH/CH₂Cl₂.Appropriate fractions were combined and evaporated to give E as a tansolid 30.4 g (94.7%).

[0220]¹ HNMR (300 MHz, CDCl₃) 0.60-0.90 (m,3H); 0.90-1.25 (m,3H); 1.48(s,6H); 2.80-3.10 (m,2H); 3.15-3.50 (m,2H); 3.80-4.20 (bs,2H); 6.72(m,1H); 6.95 (m,1H); 7.25 (m,1H). MS (ES⁺) m/z (M+H)⁺ 313.23, 315.26

[0221] A solution of E (15 g, 48 mmol) in conc HCl (48 ml) was cooled to−10° C. and to it was added drop wise a solution of NaNO₂ (3.97 g, 57.5mmol) in water (24 ml) such that the internal temperature remained <−8°C. The resulting solution was left to stir for 1 hr at this temperaturebefore it was added drop wise to a solution of SnCl₂.2H₂O (53.0 g, 235mmol) in conc HCl (36.5 ml) at −12° C. such that the internaltemperature remained <−10° C. The mixture was stirred for 2 hours at−10° C. then allowed to warm to 10° C. before it was quenched into water(600 ml), neutralised with solid NaHCO₃, filtered and extracted withEtOAc (3×400 ml). The organics were dried (MgSO₄), filtered andevaporated to a yellow oil. This was treated with 1M HCl/Et₂O and driedto give the HCl salt of F as a free flowing white powder 14.7 g (84.4%)

[0222]¹H NMR (300 MHz, DMSO-D₆) 0.50-0.85 (m,3H); 0.85-1.10 (m,3H); 1.40(s,6H); 2.70-3.00 (m,2H); 3.00-3.40(m,2H); 7.00-7.10 (m,1H);7.10-7.20(m, 1H); 7.20-7.30 (m,1H). LCMS (ES⁺) m/z (M+H)⁺ 328.3, 330.3(UV 254 nm 95%)

[0223] Preparation of Starting Materials (2)

[0224] Syntheses for starting materials G, H, I, J and K used in theabove examples are described with reference to Scheme 6 below.

[0225] n-BuLi (1.6M in Hexanes) (100 ml, 160 mmol) was added drop wiseto a stirred, cooled (−78° C.) solution of 5-Bromoxylene (21.73 ml, 160mmol) in THF (235 ml) and Et₂O (235 ml) such that the internaltemperature remained <−65° C. The resulting yellow suspension wasallowed to stir for 1.25 hours before it was added via a cannula to astirred, cooled (−78° C.) solution of—Butyrolactone (14.7 ml, 192 mmol)in THF (180 ml) such that the internal temperature remained <−70° C. Themixture was then stirred at this temperature for a further 5 hours,quenched with saturated NH₄Cl (200 ml) and extracted with Et₂O (3×100ml). The combined organics were washed with brine (2×100 ml), dried(MgSO₄), filtered and concentrated to a yellow oil. This was thenpurified by chromatography on SiO₂ (Merck 9385) eluting with 45%EtOAc/i-Hexane to give G as a pale yellow oil 15.74 g(60%).

[0226]¹H NMR (300 MHz, DMSO-D₆) 1.70 (q,2H); 2.30 (s,6H); 2.98 (t,2H);3.42 (q,2H); 4.43 (t,1H); 7.22 (s,1H); 7.52(s, 2H).

[0227] Diethyl Azodicarboxylate (22.5 ml, 143 mmol) was added drop wiseto a stirred, cooled (−5° C.) solution of G (24.0 g, 124 mmol),Phthalimide (20.0 g, 136 mmol) and Triphenylphosphine (36.0 g, 136 mmol)in THF (450 ml) such that the internal temperature remained <0° C. TheRM was stirred for 1 hr at this temperature, diluted with EtOAc (600 ml)and washed with water (250 ml) and brine (250 ml). The organics werethen dried (MgSO₄), filtered and concentrated to a yellow semi-solid.The crudes were purified by chromatography on SiO₂ (Merck 9385) elutingwith 25% EtOAc/i-Hexane to give H as a white powder 13.3 g (34%).

[0228]¹H NMR (300 MHz, DMSO-D₆) 1.80-2.00 (m,2H); 2.28 (s,6H); 3.03(t,2H); 3.62 (t,2H); 7.22 (s,1H); 7.47 (s,2H); 7.70 7.90 (m, 4H).

[0229] BF₃.Et₂O (30 ml) was added to a stirred solution of F (27.0 g, 74mmol) and H (24.4 g, 77 mmol) in AcOH (450 ml) and the resulting mixtureheated at 90 ° C. for 48 hours. The RM was evaporated to dryness and theresidues treated with saturated NaHCO₃ (100 ml). The resulting solidswere collected by filtration, triturated with MeOH/CHCl₃ andre-filtered. The filtrates were concentrated to give I as an off-whitepowder 36 g (79%).

[0230]¹H NMR (300 MHz, CDCl₃) 0.60-0.75(m,3H); 1.00-1.15 (m,3H); 1.54(s,6H); 2.25 (s,6H); 2.80-2.95 (m,2H); 3.24-3.40 (m,2H); 3.15-3.23 (m,2H); 3.80-3.90 (m,2H); 6.80 (s,1H); 7.06 (s,2H); 7.12 (s,1H); 7.45(s,1H); 7.55-7.70 (m,4H); 8.02 (s,1H). LCMS (ES⁺) m/z (M+H)⁺ 613.9,615.9 (UV 254 nm 100%)

[0231] A solution of I (42.0 g, 68 mmol) in MeOH (1000 ml) and Et₃N (10ml) was treated with 10% Pd/C (10.0 g) and stirred under H₂ (2 Bar) for48 hours. The catalyst was removed by filtration through diatomaceousearth and the filtrates evaporated. The residues were re-dissolved inEtOAc, washed with water, dried (MgSO₄), filtered and concentrated invacuo to give J as a yellow foam 32.2 g (88%).

[0232]¹H NMR (300 MHz, CDCl₃) 0.60-0.80 (m,3H); 1.05-1.25 (m,3H); 1.60(s,6H); 2.30 (s,6H); 2.85-3.05 (m,2H); 3.20-3.50 (m,4H); 3.90-4.00 (m,2H); 6.85 (s,1H); 6.95-7.05 (m,1H); 7.12 (s,2H); 7.20-7.35 (m,1H+CHCl₃);7.55-7.7 (m,3H); 7.70-7.80 (m,2H); 8.00 (s,1H). LCMS (ES⁺) m/z (M+H)⁺536.59 (UV 254 nm 100%) LCMS (ES⁻) m/z (M−H)⁻ 534.58 (UV 254 nm 100%)

[0233] Hydrazine Hydrate (40 ml, 192 mmol) was added to a stirredsolution of J (28 g, 52.3 mmol) in a mixture of MeOH (200 ml) and CH₂Cl₂(200 ml) and stirred for 48 hours at RT. A further portion of HydrazineHydrate (40 ml) was added and stirring continued for another 24 hours.The RM was filtered, washed with saturated NaHCO₃ (4×150 ml), brine(2×100 ml), dried (MgSO₄), filtered and evaporated. The crudes werepurified by flash chromatography on SiO₂ (Merck 9385) eluting with EtOAcfollowed by 10% MeOH/CH₂Cl₂ to give K as a pale yellow foam 17.1g(80.6%).

[0234]¹H NMR (300 MHz, CDCl₃) 0.60-0.80 (m,3H); 1.05-1.25 (m,3H); 1.60(s,6H); 1.76 (s,2H+H₂O); 2.38 (s,6H); 2.80-3.12 (m,6H); 3.25-3.45 (m,2H); 7.00 (s,1H); 7.02-7.07(m,1H); 7.17 (s,2H); 7.25-7.35 (m,1H); 7.42(s,1H); 8.12 (s,1H). LCMS (ES⁺) m/z (M+H)⁺ 406.56 (UV 254 nm 100%) LCMS(ES⁻) m/z (M−H)⁻ 404.57 (UV 254 nm 100%)

[0235] Diphenyl cyanocarbonimidate (1.5 g, 6.3 mmol) was added to astirred solution of K (1.5 g, 3.7 mmol) in IPA and the mixture stirred18 hours at RT. The RM was concentrated in vacuo and the residuesre-dissolved in EtOAc (150 ml). The organics were washed with saturatedNaHCO₃ (3×70 ml), brine (2×75 ml), dried (MgSO₄), filtered andevaporated. The crudes were purified by flash chromatography on SiO₂(Merck 9385) eluting with a gradient 0-5% MeOH/CH₂Cl₂ to give L as anoff-white foam 1.9 g(95.4%).

[0236]¹HMR (300 MHz, CDCl₃) 0.60-0.80 (m,3H); 1.00-1.20 (m,3H);1.55(s,6H); 2.35 (s,6H); 2.75-3.20 (m,2H); 3.10-3.45 (m, 4H); 3.60-3.75(m,2H); 6.30-6.45 (m,1M); 6.67-6.80 (m,2H); 7.00-7.50 (m,9H); 8.18(s,1H). MS (ES⁺) m/z (M+H)⁺ 550.36 MS (ES⁻) m/z (M−H)⁻ 548.30, 454.38

[0237] 1,1 Bis(methylthio)-2-nitroethylene (515 ml, 3.1 mmol) was addedto a stirred solution of K (1.1 g, 2.72 mmol) in CH₃CN (70 ml) andheated at reflux for 18 hours. The RM was concentrated in-vacuo and thecrudes purified by chromatography on SiO₂ (Merck 9385), eluting with 5%MeOH/CH₂Cl₂ to give M as a yellow foam 1.4 g(98%).

[0238]¹H NMR (300 MHz, CDCl₃) 0.60-0.80 (m,3H); 1.05-1.25 (m,3H); 1.60(s,6H); 2.38(s,6H); 2.80-3.05 (m,2H); 3.25-3.50 (m,4H); 3.68 (q,2H);6.42 (s,1H); 7.05 (s,1H); 7.06-7.15 (m,3H); 7.32 (d,1H); 7.45 (s,1H);8.11 (s,1H). MS (ES⁺) m/z (M+H)⁺ 523.44 MS (ES⁻) m/z (M−H)⁻521.49

[0239] Therapeutic Uses

[0240] Compounds of formula I are provided as medicaments forantagonising gonadotropin releasing hormone (GnRH) activity in apatient, eg, in men and/or women. To this end, a compound of formula Ican be provided as part of a pharmaceutical formulation which alsoincludes a pharmaceutically acceptable diluent or carrier (eg, water).The formulation may be in the form of tablets, capsules, granules,powders, syrups, emulsions (eg, lipid emulsions), suppositories,ointments, creams, drops, suspensions (eg, aqueous or oily suspensions)or solutions (eg, aqueous or oily solutions). If desired, theformulation may include one or more additional substances independentlyselected from stabilising agents, wetting agents, emulsifying agents,buffers, lactose, sialic acid, magnesium stearate, terra alba, sucrose,corn starch, talc, gelatin, agar, pectin, peanut oil, olive oil, cacaobutter and ethylene glycol.

[0241] The compound is preferably orally administered to a patient, butother routes of administration are possible, such as parenteral orrectal administration. For intravenous, subcutaneous or intramuscularadministration, the patient may receive a daily dose of 0.1 mgkg⁻¹ to 30mgkg⁻¹ (preferably, 5 mgkg⁻¹ to 20 mgkg⁻¹) of the compound, the compoundbeing administered 1 to 4 times per day. The intravenous, subcutaneousand intramuscular dose may be given by means of a bolus injection.Alternatively, the intravenous dose may be given by continuous infusionover a period of time. Alternatively, the patient may receive a dailyoral dose which is approximately equivalent to the daily parenteraldose, the composition being administered 1 to 4 times per day. Asuitable pharmaceutical formulation is one suitable for oraladministration in unit dosage form, for example as a tablet or capsule,which contains between 10 mg and 1 g (preferably, 100 mg and 1 g) of thecompound of the invention.

[0242] The following illustrate representative pharmaceutical dosageforms containing a compound of the invention, or a pharmaceuticallyacceptable salt or solvate thereof (hereafter referred to as “compoundX”), for use in humans.

[0243] (a) Tablet I mg/tablet Compound X. 100 Lactose Ph.Eur. 179Croscarmellose sodium 12.0 Polyvinylpyrrolidone 6 Magnesium stearate 3.0

[0244] (b) Tablet II mg/tablet Compound X 50 Lactose Ph.Eur. 229Croscarmellose sodium 12.0 Polyvinylpyrrolidone 6 Magnesium stearate 3.0

[0245] (c) Tablet III mg/tablet Compound X 1.0 Lactose Ph.Eur. 92Croscarmellose sodium 4.0 Polyvinylpyrrolidone 2.0 Magnesium stearate1.0

[0246] (d) Capsule mg/capsule Compound X 10 Lactose Ph.Eur. 389Croscarmellose sodium 100 Magnesium stearate 1.

[0247] (e) Injection I (50 mg/ml) Compound X 5.0% w/v Isotonic aqueoussolution to 100%

[0248] Buffers, pharmaceutically acceptable co-solvents (eg,polyethylene glycol, propylene glycol, glycerol or EtOH) or complexingagents such as hydroxy-propyl β cyclodextrin may be used to aidformulation.

[0249] One aspect of the invention relates to the use of compoundsaccording to the invention for reducing the secretion of LH and/or FSHby the pituitary gland of a patient. In this respect, the reduction maybe by way of a reduction in biosynthesis of the LH and FSH and/or areduction in the release of LH and FSH by the pituitary gland. Thus,compounds according to the invention can be used for therapeuticallytreating and/or preventing a sex hormone related condition in thepatient. By “preventing” we mean reducing the patient's risk ofcontracting the condition. By “treating” we mean eradicating thecondition or reducing its severity in the patient. Examples of sexhormone related conditions are: a sex hormone dependent cancer, benignprostatic hypertrophy, myoma of the uterus, endometriosis, polycysticovarian disease, uterine fibroids, prostatauxe, myoma uteri, hirsutismand precocious puberty. Examples of sex hormone dependent cancers are:prostatic cancer, uterine cancer, breast cancer and pituitarygonadotrophe adenoma.

[0250] The compounds of the invention may be used in combination withother drugs and therapies used to treat/prevent sex-hormone relatedconditions.

[0251] If formulated as a fixed dose such combination products employthe compounds of this invention within the dosage range described hereinand the other pharmaceutically-active agent within its approved dosagerange. Sequential use is contemplated when a combination formulation isinappropriate.

[0252] In the field of medical oncology examples of such combinationsinclude combinations with the following categories of therapeutic agent:

[0253] i) anti-angiogenic agents (for example linomide, inhibitors ofintegrin αvβ3 function, angiostatin, endostatin, razoxin, thalidomide)and including vascular endothelial growth factor (VEGF) receptortyrosine kinase inhibitors (RTKIs) (for example those described ininternational patent applications publication nos. WO-97/22596,WO-97/30035, WO-97/32856 and WO-98/13354, the entire disclosure of whichdocuments is incorporated herein by reference);

[0254] ii) cytostatic agents such as anti-oestrogens (for exampletamoxifen, toremifene, raloxifene, droloxifene, iodoxyfene),progestogens (for example megestrol acetate), aromatase inhibitors (forexample anastrozole, letrozole, vorazole, exemestane),anti-progestogens, anti-androgens (for example flutamide, nilutamide,bicalutamide, cyproterone acetate), inhibitors of testosterone5α-dihydroreductase (for example finasteride), anti-invasion agents (forexample metalloproteinase inhibitors like marimastat and inhibitors ofurokinase plasminogen activator receptor function) and inhibitors ofgrowth factor function, (such growth factors include for exampleepidermal growth factor (EGF), platelet derived growth factor andhepatocyte growth factor such inhibitors include growth factorantibodies, growth factor receptor antibodies, tyrosine kinaseinhibitors and serine/threonine kinase inhibitors);

[0255] iii) biological response modifiers (for example interferon);

[0256] iv) antibodies (for example edrecolomab); and

[0257] v) anti-proliferative/anti-neoplastic drugs and combinationsthereof, as used in medical oncology, such as anti-metabolites (forexample anti-folates like methotrexate, fluoropyrimidines like5-fluorouracil, purine and adenosine analogues, cytosine arabinoside);anti-tumour antibiotics (for example anthracyclines like doxorubicin,daunomycin, epirubicin and idarubicin, mitomycin-C, dactinomycin,mithramycin); platinum derivatives (for example cisplatin, carboplatin);alkylating agents (for example nitrogen mustard, melphalan,chlorambucil, busulphan, cyclophosphamide, ifosfamide, nitrosoureas,thiotepa); anti-mitotic agents (for example vinca alkaloids likevincristine and taxoids like taxol, taxotere); enzymes (for exampleasparaginase); thymidylate synthase inhibitors (for exampleraltitrexed); topoisomerase inhibitors (for example epipodophyllotoxinslike etoposide and teniposide, amsacrine, topotecan, irinotecan).

[0258] The compounds of the invention may also be used in combinationwith surgery or radiotherapy.

[0259] Assays

[0260] The ability of compounds according to the invention to act asantagonists of GnRH can be determined using the following in vitroassays.

[0261] Binding Assay Using Rat Pituitary GnRH Receptor

[0262] The assay is performed as follows:-

[0263] 1. Incubate crude plasma membranes prepared from rat pituitarytissues in a Tris.HCl buffer (pH. 7.5, 50 mM) containing bovine serumalbumin (0.1%), [I-125]D-t-Bu-Ser6-Pro9-ethyl amide-GnRH, and the testcompound. Incubation is at 4° C. for 90 minutes to 2 hours.

[0264] 2. Rapidly filter and repeatedly wash through a glass fibrefilter.

[0265] 3. Determine the radioactivity of membrane bound radio-ligandsusing a gamma counter.

[0266] From this data, the IC₅₀ of the test compound can be determinedas the concentration of the compound required to inhibit radio-ligandbinding to GnRH receptors by 50%. Compounds according to the presentinvention have activity at a concentration from 1 nM to 5 μM.

[0267] Binding Assay Using Human GnRH Receptor

[0268] Crude membranes prepared from CHO cells expressing human GnRHreceptors are sources for the GnRH receptor. The binding activity ofcompounds according to the invention can be determined as an IC₅₀ whichis the compound concentration required to inhibit the specific bindingof [¹²⁵I]buserelin to GnRH receptors by 50%. [¹²⁵I]Buserelin (a peptideGnRH analogue) is used here as a radiolabelled ligand of the receptor.

[0269] Assay to Determine Inhibition of LH Release

[0270] The LH release assay can be used to demonstrate antagonistactivity of compounds, as demonstrated by a reduction in GnRH-induced LHrelease.

[0271] Preparation of Pituitary Glands

[0272] Pituitary glands obtained from rats are prepared as follows.Suitable rats are Wistar male rats (150-200 g) which have beenmaintained at a constant temperature (eg, 25° C.) on a 12 hour light/12hour dark cycle. The rats are sacrificed by decapitation before thepituitary glands are aseptically removed to tube containing Hank'sBalanced Salt Solution (HBSS). The glands are further processed by:-

[0273] 1. Centrifugation at 250×g for 5 minutes;

[0274] 2. Aspiration of the HBSS solution;

[0275] 3. Transfer of the glands to a petri dish before mincing with ascalpel;

[0276] 4. Transfer of the minced tissue to a centrifuge tube bysuspending the tissue three successive times in 10 ml aliquots of HBSScontaining 0.2% collagenase and 0.2% hyaluronidase;

[0277] 5. Cell dispersion by gentle stirring of the tissue suspensionwhile the tube is kept in a water bath at 37° C.;

[0278] 6. Aspiration 20 to 30 times using a pipette, undigestedpituitary fragments being allowed to settle for 3 to 5 minutes;

[0279] 7. Aspiration of the suspended cells followed by centrifugationat 1200×g for 5 minutes;

[0280] 8. Re-suspension of the cells in culture medium of DMEMcontaining 0.37% NaHCO₃, 10% horse serum, 2.5% foetal bovine serum, 1%non essential amino acids, 1% glutamine and 0.1% gentamycin;

[0281] 9. Treatment of the undigested pituitary fragments 3 times with30 ml aliquots of the collagenase and hyaluronidase;

[0282] 10. Pooling of the cell suspensions and dilution to aconcentration of 3×10⁵ cells/ml;

[0283] 11. Placing of 1.0 ml of this suspension in each of a 24 welltray, with the cells being maintained in a humidified 5% CO₂/95% airatmosphere at 37° C. for 3 to 4 days

[0284] Testing of Compounds

[0285] The test compound is dissolved in DMSO to a final concentrationof 0.5% in the incubation medium.

[0286] 1.5 hours prior to the assay, the cells are washed three timeswith DMEM containing 0.37% NaHCO₃, 10% horse serum, 2.5% foetal bovineserum, 1% non essential amino acids (100×), 1% glutamine (100×), 1%penicillin/streptomycin (10,000 units of each per ml) and 25 mM HEPES atpH 7.4. Immediately prior to the assay, the cells are again washed twicein this medium.

[0287] Following this, 1 ml of fresh medium containing the test compoundand 2 nM GnRH is added to two wells. For other test compounds (where itis desired to test more than one compound), these are added to otherrespective duplicate wells. Incubation is then carried out at 37° C. forthree hours.

[0288] Following incubation, each well is analysed by removing themedium from the well and centrifuging the medium at 2000×g for 15minutes to remove any cellular material. The supernatant is removed andassayed for LH content using a double antibody radio-immuno assay.Comparison with a suitable control (no test compound) is used todetermine whether the test compound reduces LH release. Compoundsaccording to the present invention have activity at a concentration from1 nM to 5 μM.

1. A compound of formula I or a salt, pro-drug or solvate thereof

wherein for A, either: (i) A represents hydrogen oroptionally-substituted C₁ to C₈ alkyl; or (ii) the structure N—A(—R⁴)represents an optionally-substituted 3- to 8-membered heterocyclic ringoptionally containing from 1 to 3 further heteroatoms independentlyselected from O, N and S; B represents a direct bond or optionallysubstituted C₁ to C₅ alkylene; C represents a mono- or bi-cyclicaromatic ring structure optionally having at least one substituentselected from CN, NR⁵R⁶, an optionally substituted C₁ to C₈ alkyl,optionally substituted C₁ to C₈ alkoxy or halo; D represents hydrogen;optionally substituted C₁ to C₈ alkyl; or (CH₂)_(b)—R^(a), wherein R^(a)is C₃ to C₈ cycloalkyl and b represents zero or an integer from 1 to 6;E is selected from an optionally substituted 3- to 8-memberedheterocyclic ring containing from 1 to 4 heteroatoms independentlyselected from O, N and S; or a group of formula II; m; IV; V; VI, VII orVIII

 wherein het represents an optionally substituted 3- to 8-memberedheterocyclic ring containing from 1 to 4 heteroatoms independentlyselected from O, N and S; for X and Y, either: (iii) X represents N andY represents CN; hydrogen or —CONR^(b)R^(c) where R^(b) and R^(c) areindependently selected from hydrogen and C₁ to C₈ alkyl; (iiia) Xrepresents CH and Y represents NO₂; or (iv) X—Y represents O; For R¹ andR², either: (v) R¹ and R² are independently selected from hydrogen andoptionally substituted C₁ to C₈ alkyl; or (vi) R¹ and R² togetherrepresent carbonyl; or (vii) R¹

B—N—R³ represents an optionally substituted 3- to 8-memberedheterocyclic ring containing from 1 to 3 further heteroatomsindependently selected from O, N and S, and R² meets the definition inoption (v); R³ meets the definition in option (vii) or representshydrogen or optionally substituted C₁ to C₈ alkyl; R⁴ meets thedefinition in option (ii), or when A meets the definition in option (i)R⁴ represents hydrogen or optionally substituted C₁ to C₈ alkyl; R⁵ andR⁶ are independently selected from hydrogen; optionally substituted C₁to C₈ alkyl and optionally substituted aryl; for R⁷ and R^(7a), either:(viii) R⁷ and R^(7a) are independently selected from hydrogen oroptionally substituted C₁ to C₈ alkyl; or ix)

 represents an optionally substituted 3 to 7-membered cycloalkyl ring;for R⁸ and R⁹, either: (x) R⁸ is selected from hydrogen; optionallysubstituted C₁ to C₈ alkyl; optionally substituted aryl; —R^(d)—Ar,where R^(d) represents C₁ to C₈ alkylene and Ar represents optionallysubstituted aryl; and an optionally substituted 3- to 8-memberedheterocyclic ring optionally containing from 1 to 3 further heteroatomsindependently selected from O, N and S; and R⁹ is selected fromhydrogen; optionally substituted C₁ to C₈ alkyl and optionallysubstituted aryl; (xi) wherein E represents a group of formula II orIII, then the group NR⁸(—R⁹) represents an optionally substituted 3- to8-membered heterocyclic ring optionally containing from 1 to 3 furtherheteroatoms independently selected from O, N and S; or (xii)wherein Erepresents structure VI,

 represents an optionally substituted 3- to 8-membered heterocyclic ringoptionally containing from 1 to 4 heteroatoms independently selectedfrom O, N and S; with the proviso that: when A is C₁ to C₈ alkyl or thestructure N—A(—R⁴) represents an optionally-substituted 3- to 8-memberedheterocyclic ring containing from 1 to 3 heteroatoms independentlyselected from O, N and S; X represents N and Y represents CN orhydrogen, X represents CH and Y represents NO₂ or X—Y represents O; thenthe optional substituents on A are not selected from optionallysubstituted phenyl or an optionally-substituted 3- to 8-memberedheterocyclic ring.
 2. The compound of claim 1, wherein —N—A(—R⁴) meetsthe definition in option (ii) and is selected from anoptionally-substituted group of formula IX, X or XI,


3. The compound of claim 2, wherein —N—A(—R⁴) is selected from XII orXIII

wherein R¹² represents C₁ to C₈ alkyl; —CH₂)_(c)NR^(e)R^(f), where c iszero or an integer from 1 to 4, and R^(e) and R^(f) independentlyrepresent hydrogen or C₁ to C₈ alkyl; hydroxy; halo; CN; C₁ to C₈alkoxy; or CF₃.
 4. The compound of claim 1, wherein A and R⁴ eachrepresent hydrogen.
 5. The compound of any preceding claim, wherein, Erepresents (a) structure II of the sub-formula

 wherein Me represents methyl; (b) structure II, wherein

 represents cyclopropyl or cyclobutyl; or (c) structure VIII wherein R⁷and R^(7a) each represent methyl.
 6. The compound of any precedingclaim, wherein C represents

wherein Me represents methyl.
 7. The compound of any preceding claim,wherein R¹ and R² each represent hydrogen and B represents C₁_(alkylene.)
 8. The compound of claim 1, wherein the compound isselected from a compound of formula XXI to XXXI

or salt, pro-drug or solvate thereof.
 9. A compound, or salt, pro-drugor solvate thereof, according to any preceding claim for use as amedicament.
 10. A pharmaceutical formulation comprising a compound, orsalt, pro-drug or solvate thereof, according to any one of claims 1 to 8and a pharmaceutically acceptable diluent or carrier.
 11. Use of acompound, or salt, pro-drug or solvate thereof, according to any one ofclaims 1 to 8, in the manufacture of a medicament for antagonisinggonadotropin releasing hormone activity.
 12. Use of a compound, or salt,pro-drug or solvate thereof, according to any one of claims 1 to 8, inthe manufacture of a medicament for administration to a patient, forreducing the secretion of luteinizing hormone by the pituitary gland ofthe patient.
 13. Use of a compound, or salt, pro-drug or solvatethereof, according to any one of claims 1 to 8, in the manufacture of amedicament for administration to a patient, for therapeutically treatingand/or preventing a sex hormone related condition in the patient. 14.The use according to claim 13, wherein the sex hormone related conditionis selected from a sex hormone dependent cancer, benign prostatichypertrophy or myoma of the uterus.
 15. The use according to claim 14,wherein the sex hormone dependent cancer is selected from prostaticcancer, uterine cancer, breast cancer and pituitary gonadotropheadenoma.
 16. A method of antagonising gonadotropin releasing hormoneactivity in a patient, comprising administering to the patient acompound, or salt, pro-drug or solvate thereof, according to any one ofclaims 1 to
 8. 17. A process of producing a compound, or salt, pro-drugor solvate thereof, according to any one of claims 1 to 8, wherein theprocess comprises a reaction step selected from any one of steps (a) to(e): (a) Reaction of a compound of formula XXXII as follows

(b) Cleavage of the CN group of a compound of formula XXXIII in thepresence of acid to produce a compound of formula XXXIV

(c) Reaction of a compound of formula XXXV as follows

(d) Reaction of a compound of formula XXXVII as follows

(e) Reaction of a compound of formula XXXIX as follows

 and thereafter if necessary: i) converting a compound of the formula Iinto another compound of the formula I; ii) removing any protectinggroups; iii) forming a salt, pro-drug or solvate.